A washing operation for washing soiled wash items, for example kitchen utensils in the form of plates, glasses, cutlery, saucepans, usually comprises the steps:
washing of the wash items with a detergent-containing washing liquid
rinsing of the wash items with a rinsing liquid so that residues of the washing liquid, and any food remnants in the washing liquid, shall be rinsed away.
For an effective rinse, the rinsing liquid is often heated. In addition, it is normal for it to contain a drying agent, which reduces the surface tension of the rinsing liquid and thus makes it easier for the rinsing liquid to run off the wash items after the rinse. The consumption of rinsing liquid, and, where appropriate, of rinsing liquid chemicals such as drying agent, as well as of energy for heating the rinsing liquid, accounts for an appreciable share of the operating costs for a dishwasher.
WO2005/020782 describes a dishwasher with reduced rinsing liquid consumption. This is achieved by the dishwasher in WO2005/020782 being provided with a collecting device for used rinsing liquid, and with a recirculating rinse tank having an inlet connected to the collecting device. The collected rinsing liquid is used to rinse the wash items in a pre-rinse phase, whereafter a final rinse of the wash items is realized with new, clean final-rinse liquid in a final-rinse phase. A float valve with delayed opening ensures that the very first pre-rinse liquid, which is dirtiest, is not allowed to enter the recirculating rinse tank, but instead runs down into the wash tank.